1. Field of the Invention
The present invention relates to gearshift actuators for bicycles and, more particularly, a rotary gearshift actuator having a stationary housing, a rotatable housing and a latching mechanism for interlocking the stationary and rotatable housings.
2. Description of the Related Art
Conventional multiple-gear bicycles employ a derailleur to transfer a bicycle drive chain from one gear sprocket to another. The derailleur is connected to a gearshift actuator through a derailleur control cable so that a bicyclist can select a desired gear by manipulating the gearshift actuator. The gearshift actuator controls movement of the derailleur by adjusting the control cable. For example, pulling the control cable causes the derailleur to shift the drive chain to a larger sprocket, and releasing the control cable permits a return spring to resiliently urge the derailleur to shift the drive chain to a smaller sprocket.
Prior art gearshift actuators, especially those mounted on the handlebar, are convenient to use; however, they do not permit easy installation or replacement of the control cable. For example, DE 44 20 125 A1 discloses a rotary handle gearshift actuator including a handle housing having two half-shell portions, a rotary ring and a carrier affixed to the rotary ring. The handle housing and the rotary ring are connected to each other in the axial direction. Thus, after the handle housing is placed at an end of the handlebar, the rotary ring cannot be easily detached because of the axial joining connection.